Apparatus for testing telephone receivers



Jan. 5 1926. 1,568,827

.w. H GERNS APPARATUS FOR TESTING TELEPHOQE RECEIVERS Filed June 21, 1924 @1 23/ um: l4

W/LL/AM H. GERNS INVENTOR.

A TTORNE Y.

Patented Jan. 5, 1926.

NIT D sures WILLIAM H. GEBNS, OF EAST ORANGE, NEW JERSEY, ASSIGNOB, BY MESH]! A8- SIGNMENTS, TO BRANDES LABORATORIES, INCL, OF

CORPORATION OF NEW JERSEY.

NEWARK, NEW JERSEY, A

APPARATUS FOR TESTING TELEPHONE RECEIVERS.

Application filed June 21,

To all whom it may concern:

Be it known that I, WILLIAM H. GnRNs, a citizen of the United States, residing at East Orange, in the county of Essex anda State of.New Jersey, have invented certain new and useful Improvements in Apparatus for Testing Telephone Receivers, of which the following is a s ecification.

. My invention re ates broadly to testing 10 apparatus for determining the properties and characteristics of acoustic instruments and more particularly to a test board unit for testing tele hone receivers.

One of the 0 jects of my invention is, to

rovide a test board unit for visual testing apparatus for telephone receivers upon which telephone receivers to be tested maybe quickly mounted in succession with relation to a standard telephone receiver unit, the test tele hone receivers being electrically connecte in a testing circuit simultaneously with the positioning of the telephone receiver with relation to the standard telephone receiver.

i Another object of my invention is to provide a test board unit for telephone receivers including a control switch and a guide block for telephone receivers mounted ad acent each other whereby the switch mechanism may be operated simultaneously with the movement of the telephone receiver to he tested into th ide block.

' Still another 0 ject of my invention is to rovide a construction of test board unit or telephone receivers-where a standard telephone receiver unit 01? known electrical characteristics and properties is positioned in suchmanner that a telephone receiver to be tested may be quickly aligned with the 40 standard telephone receiver and simultaneously connected in a testing circuit whereby sound vibrations generated by either the standard or the tele hone receiver to be tested may be directe immediately against .45 the diaphragm of the other telephone, re-

ceiver. y My invention also has for an object the provision of a compact test board including an anti-capacity switch mechanism and a standard telephone receiver of known electrical properties with a guide blockmounted adjacent the standard telephone ,recelver in a position directly over the standard telephone recelver in such manner that a tele 1924. Serial at. 721,462.

phone to be tested may be readily slipped into place over the standard receiver and the switch mechanism simultaneously operated for connecting the telephone receiver to be tested in the electrical circuits.

M invention will be more fully under.- stoo from the following specifications by reference to the. accompanying drawings, in which:

Figure 1 is a top plan view of the test board unit; Fig. 2 is a side view of the test board unit showing the standard telephone receiver in position; and, Fi 3, is an end view of the test board unit ilustrated in Figs. 1 and 2.

The embodiment of my invention as herein described has been found to be one of the practical forms of the invention capable of eflicient operation and practical in construction. It will be understood however, that the invention may be embodied in other forms than that herein described and that I do not intend my invention to be limited to the particular form illustrated.

Referring to the drawings in detail the test board unit is shown as consisting of a plate 1 which may be readily secured to the panel of a visual testing apparatus' A pad 2 for the test plate 1 is provided as shown In Fig. 1, extending over one edge of plate 1 as illustrated in Figs. 2 and 3. The anticapacityswitch Sis mounted adjacent the pad 2 with an o crating rocker knob 4 extending u ward y fromv the anel v1. A guide 5, c osed on three sides ut open on the remaining side and having an interior contour shaped to receive atelephone re ceiver whose characteristics are to be determined, is mounted upon pad 2 and secured to plate 1 as represented at 5. The inner contour of the guide 5 is such that a telephone receiver when laced with its cap in contact with the sur of the pad 2,

will snugly fit with the edges of the cap contacting with the interior walls of the 5. On one side of the 'de 5, I' mount an insulated guide block 12 on the extremity of e telephone receiver casing carries terguide member 11,

guide minals'17 and 18 projecting from the rear thereof one s aced from the other substantially the wi th of the guide member 11.

On either side of the insulated guide block 12 I mount a U shaped member 7 and 8 consisting of a brush holder. One flat side of each of the U shaped members is secured on the guide 5 while on the opposite fiat side of the U shaped members I attach resilient brushes 9 an 10 respectively. The brushes 9 and 10project laterally in a direction corresponding to that in which guide member 11 extends. Each brush 9 an 10 may consist of a plurality of leaves of s ring mate rial having a length just short 0 the length of guide member 11 but reaching to a point where terminals 17 and 18 will contact with the brushes 9 and 10 res ectively. The brushes 9 and 10 are secured to brush holders 7 and 8 respectively by any suitable means such as screws 9 and 10*. Binding osts 9 and 10 may be secured to the brush olders for making connections across the telephone receiver to be tested although normally connections from the brush holders are taken from beneath the plate 1.

A standard telephone receiver 15 is mounted beneath the plate 1 and secured in position by suitable means such as a receiver clamp or bracket 14. The standard telephone receiver 15 faces upwardly while the test receiver 16 faces downwardly in such manner that either one or the other may 0 erate as a generator of sound vibrations elivering such vibrations to the other through an a erture aligned with the centers of both t e telephone receivers 15 and 16 through the plate 1.

The anti-capacity switch 3 has a frame 19 depending from the plate 1 and carrying a plurality of resilient contacts 40, 41, 42, and 43 positioned in pairs adjacent each other. A (pair of leaf spring contact members 21 an 22 engage a cam member 23 carried by the switch knob 4 pivoted at 20 in such manner that knob 4 may be rocked from side to side to connect the telephone receivers in various circuit arrangements, the standard tele hone receiver 15 in tests for sensitivity of t e telephone receiver 16 being employed as a enerator of sound vibrations while the telep one receiver 16 whose properties are to be determined being employed as the generator of sound vibrations in volume tests. In order to accomplish a rapid change over in test for volume and sensitivity the switch knob 4 is arranged immediately adjacent the guide member 5 so that the hand of the operator in sliding the telephone receiver 16 into test position may also move switch knob 4 to the desired position for testing either the sensitivity or volume characteristics of the telephone receiver in comparison to the known standard 15. It will be understood that the cooperation of the anti-capacity control switch 4 and the quick connection guide block for the telephone receivers to be tested, enables the rapid testing of telephone receivers in quantity production for acceptance or rejection.

It will be understood that the guide herein described for use with telephone re-' ceivers having terminals in the rear of the casing may also be constructed for use with telephone receivers having terminals interior of the casing in which event the laterally projecting brushes 9 and 10 may extend into the side of the telephone receiver casing to a suflicient distance to contact with the terminals of the receiver interior of the casing. Other modifications upon the invention ma be made and I intend no limitations other than are imposed by the scope of the appended claims.

What I claim and desire to secure by Letters Patent of the United States is as follows:

1. A test board unit for telephone receivers, comprising in combination an 9. ertured panel, a standard telephone receiver adapted to befixedly secured in a position where sound vibrations may be delivered or received through said apertured panel, a guide block for tele hone receivers whose properties are to be dhtermined mounted on the opposite side of said apertured panel concentric with the mounting of said standard tele )hone receiver, and a pair of resilient lea springs positioned at one side of said guide block whereby a tele hone receiver to be tested may be slippe into said guide block and connections simultaneously established between the terminals of the telephone receiver to be tested and said resilient leaf slprings, whereby sound vibrations from sai telephone receiver to be tested may be delivered or received through said apertured panel.

2. A test hoard unit for telephone receivers, comprising in combination an apertured panel, a standard telephone receiver adapted to be fixedly secured in a position where sound vibrations may be delivered or received through said apertured panel, a guide block or telephone receivers whose properties are to be determined mounted on the opposite side of said apertured panel concentric with the mounting of said stand ard telephone receiver, and a pair of brush holders mounted on one side csaid guide block, a laterally extending brush secured to each of said brush holders whereby a telephone receiver whose properties are to be tested may be slipped into said guide block and connections snnultaneously established with said brushes whereby sound vibrations from said receiver on test may be delivered or received through said apertured panel.

3. A test board unit for telephone receivers, comprising in combination an apertured panel, a standard tele hone'receiver adapted to be fixedly secure in a position ,the opposite side of said apertured panel concentric with ,themoun'ting of said standard telephone receiver, and a. pair of U shaped brush'holders, each having one side thereof secured to said guide block and each carrying on the other side thereof a laterally extending brush whereby a telephone receiver whose properties are to be determined may be slipped into said guide block and connections established with said brushes, sound vibrations being passed between said standard telephone receiver and said receiver on test in either direction through said apertured panel.

4. A test board unit for telephone receivers, comprising in combination an apertured panel, a standard telephone receiver 7 adapted to befixedly secured in a position where sound vibrations may be delivered or received through said apertured panel, a guide block for telephone receivers whose properties are to be determined mounted on the opposite side of said apertured panel concentric with the mounting of said standard telephone receiver, and a pair ofbrush holders, one spaced from the other mounted on said guide block, an insulated member positioned between said brush holders, an insulated laterally extending guide member secured to said insulated member and a laterally extending brush carried b each of said brush holders on opposite si es of said insulated guide member whereby a telephone receiver whos'e properties are to be determined may be slipped into said guide block and connections established with said brushes, sound vibrations being passed between said telephone receiver on test and said standard telephone receiver ineither direction through said apertured panel.

WILLIAM H. GERNS. 

